Deflation is a decrease in the general price level of goods and services in an economy over a period of time. This means that less money is needed to purchase the same quantity of goods and services. Deflation can occur due to various reasons such as decreased demand, increased supply, technological advancements, or a decrease in the money supply.

In an economy, deflation can have both positive and negative effects. On one hand, deflation can reduce the cost of production for firms, increase the purchasing power of consumers, and encourage saving, which can lead to investments. On the other hand, deflation can lead to a decrease in consumer spending, decrease in profits for firms, and increase the level of debt for borrowers.

Deflation can also have implications for the industry. For instance, during deflation, some industries may be affected more than others. In industries where prices are highly rigid, deflation could lead to a reduction in production and job layoffs. Similarly, in industries that rely on borrowing, deflation could lead to an increase in the real value of borrowing, which could make it difficult to repay loans.

To summarize, deflation refers to a sustained decrease in the general price level of goods and services in an economy. It can have both positive and negative effects on the economy and different industries may be affected differently during deflation.